English
Related papers

Related papers: Efficient Estimation of Regularized Tyler's M-Esti…

200 papers

Focusing on identification, this paper develops a class of convex optimization-based criteria and correspondingly the recursive algorithms to estimate the parameter vector $\theta^{*}$ of a stochastic dynamic system. Not only do the…

Optimization and Control · Mathematics 2024-05-14 Mingxia Ding , Wenxiao Zhao , Tianshi Chen

Consider the following class of learning schemes: \begin{equation} \label{eq:main-problem1} \hat{\boldsymbol{\beta}} := \underset{\boldsymbol{\beta} \in \mathcal{C}}{\arg\min} \;\sum_{j=1}^n \ell(\boldsymbol{x}_j^\top\boldsymbol{\beta};…

Machine Learning · Computer Science 2018-10-08 Shuaiwen Wang , Wenda Zhou , Arian Maleki , Haihao Lu , Vahab Mirrokni

It is common to subsample Markov chain output to reduce the storage burden. Geyer (1992) shows that discarding $k-1$ out of every $k$ observations will not improve statistical efficiency, as quantified through variance in a given…

Computation · Statistics 2017-04-12 Art B. Owen

Much research has been carried out on shrinkage methods for real-valued covariance matrices. In spectral analysis of $p$-vector-valued time series there is often a need for good shrinkage methods too, most notably when the complex-valued…

Statistics Theory · Mathematics 2015-10-28 A. T. Walden , D. Schneider-Luftman

This article studies two regularized robust estimators of scatter matrices proposed (and proved to be well defined) in parallel in (Chen et al., 2011) and (Pascal et al., 2013), based on Tyler's robust M-estimator (Tyler, 1987) and on…

Probability · Mathematics 2015-01-20 Romain Couillet , Matthew R. McKay

Margin maximization in the hard-margin sense, proposed as feature elimination criterion by the MFE-LO method, is combined here with data radius utilization to further aim to lower generalization error, as several published bounds and…

Machine Learning · Statistics 2014-05-13 Yaman Aksu

One of the major challenges in multivariate analysis is the estimation of population covariance matrix from sample covariance matrix (SCM). Most recent covariance matrix estimators use either shrinkage transformations or asymptotic results…

Methodology · Statistics 2019-12-10 Samruddhi Deshmukh , Amartansh Dubey

Stochastic PDE eigenvalue problems are useful models for quantifying the uncertainty in several applications from the physical sciences and engineering, e.g., structural vibration analysis, the criticality of a nuclear reactor or photonic…

Numerical Analysis · Mathematics 2022-10-07 Alexander D. Gilbert , Robert Scheichl

We propose Subsampling MCMC, a Markov Chain Monte Carlo (MCMC) framework where the likelihood function for $n$ observations is estimated from a random subset of $m$ observations. We introduce a highly efficient unbiased estimator of the…

Methodology · Statistics 2018-12-31 Matias Quiroz , Robert Kohn , Mattias Villani , Minh-Ngoc Tran

A smoothing algorithm is presented for solving the soft-margin Support Vector Machine (SVM) optimization problem with an $\ell^{1}$ penalty. This algorithm is designed to require a modest number of passes over the data, which is an…

Optimization and Control · Mathematics 2024-01-19 Ibrahim Emirahmetoglu , Jeffrey Hajewski , Suely Oliveira , David E. Stewart

In this paper, a general class of regularized $M$-estimators of scatter matrix are proposed which are suitable also for low or insufficient sample support (small $n$ and large $p$) problems. The considered class constitutes a natural…

Applications · Statistics 2015-06-19 Esa Ollila , David E. Tyler

Posterior inference with an intractable likelihood is becoming an increasingly common task in scientific domains which rely on sophisticated computer simulations. Typically, these forward models do not admit tractable densities forcing…

Machine Learning · Statistics 2020-06-29 Joeri Hermans , Volodimir Begy , Gilles Louppe

Owing to the edge preserving ability and low computational cost of the total variation (TV), variational models with the TV regularization have been widely investigated in the field of multiplicative noise removal. The key points of the…

Computer Vision and Pattern Recognition · Computer Science 2015-03-18 Dai-Qiang Chen , Li-Zhi Cheng

In the world of targeted learning, cross-validated targeted maximum likelihood estimators, CV-TMLE [Zheng:2010aa], has a distinct advantage over TMLE [Laan:2006aa] in that one less condition is required of CV-TMLE in order to achieve…

Methodology · Statistics 2018-11-14 Jonathan Levy

Recently-proposed particle MCMC methods provide a flexible way of performing Bayesian inference for parameters governing stochastic kinetic models defined as Markov (jump) processes (MJPs). Each iteration of the scheme requires an estimate…

Computation · Statistics 2014-05-19 Andrew Golightly , Daniel A. Henderson , Chris Sherlock

This paper considers the problem of robustly estimating a structured covariance matrix with an elliptical underlying distribution with known mean. In applications where the covariance matrix naturally possesses a certain structure, taking…

Applications · Statistics 2016-06-29 Ying Sun , Prabhu Babu , Daniel P. Palomar

The primary objective of this scholarly work is to develop two estimation procedures - maximum likelihood estimator (MLE) and method of trimmed moments (MTM) - for the mean and variance of lognormal insurance payment severity data sets…

Methodology · Statistics 2024-02-22 Chudamani Poudyal

Linear shrinkage estimators of a covariance matrix --- defined by a weighted average of the sample covariance matrix and a pre-specified shrinkage target matrix --- are popular when analysing high-throughput molecular data. However, their…

Methodology · Statistics 2018-09-24 Harry Gray , Gwenaël G. R. Leday , Catalina A. Vallejos , Sylvia Richardson

In this article we consider the smoothing problem for hidden Markov models (HMM). Given a hidden Markov chain $\{X_n\}_{n\geq 0}$ and observations $\{Y_n\}_{n\geq 0}$, our objective is to compute…

Methodology · Statistics 2018-04-20 Jeremie Houssineau , Ajay Jasra , Sumeetpal S. Singh

This paper presents a detailed theoretical analysis of the three stochastic approximation proximal gradient algorithms proposed in our companion paper [49] to set regularization parameters by marginal maximum likelihood estimation. We prove…

Statistics Theory · Mathematics 2020-08-14 Valentin De Bortoli , Alain Durmus , Ana F. Vidal , Marcelo Pereyra